A mobile processor module ("MPM") is a multi-component device that plugs into a PC motherboard. Conventional MPMs contain a voltage regulator, a central processing unit ("CPU"), a cache, and a system controller. FIG. 1 shows an architecture block diagram of an MPM produced by the Intel Corporation. This MPM 101 contains a Pentium.RTM. processor 102, a L2 cache SRAM 103, a tag RAM 104, a voltage regulator 105, and a MCTX "North Bridge" system controller 106. This MPM interfaces to DRAM memory 107 via a memory bus 108 and to other devices within the PC system via a port 114 to PCI bus 109. An internal CPU bus 113 connects the CPU 102, cache SRAM 103, and system controller 106. Other devices coupled to the PCI bus 113 may include a PCI-ISA bridge 110, a video graphics accelerator ("VGA") controller 111, and other PCI-compatible system components 112. The PCI bus 109 in current systems generally runs at a clock speed of 33 MHz. The structure and operation of the above-described components are conventional. Therefore, an explanation of their structure and operation will be omitted in the interest of brevity.
VGA controllers are currently available that can run either at a clock speed of 33 MHz or a clock speed of 66 MHz. Increased clock speeds for VGA controllers result in increased rate of data transfer from a MPM 101 to a VGA display monitor controlled by the faster VGA controller 111. Increased data transfer rates are important for enhanced multimedia computer applications and graphical user interfaces that display detailed animation and real-time video images.
In order to take a better advantage of VGA controllers that run at higher clock speeds, as well as to take advantage of the increased performance and capabilities of the Pentium.RTM. II processor, Intel may produce an enhanced MPM that will be herein referred to as a model MDM-A MPM. FIG. 2 shows an architecture block diagram of the Intel MDM-A enhanced MPM. Many of the components shown in FIG. 2 are identical to components shown in FIG. 1. Thus, in the interest of brevity, these components of FIG. 2 that are identical to components in FIG. 1 have been provided with the same reference numerals as in FIG. 1, and an explanation of their operation will not be repeated. The MDM-A 201 contains a cache SRAM 202, a Pentium.RTM. II CPU 203, a voltage regulator 204, and an Intel 440 BX "North Bridge" system controller 205. The system controller 205 is connected to DRAM memory 107 via a memory bus 108. The system controller 205 has two ports 213 and 214 for coupling to external devices. As in the MPM 101 shown in FIG. 1, most PCI-compatible devices 112 and a PCI-ISA bridge 110 are connected to the system controller 205 via a PCI bus 109. This PCI bus 109 runs at 33 MHz. Unlike the MPM 101 shown in FIG. 1, the MDM-A system controller 205 has a second port 214 coupled to an advanced graphics processor ("AGP") bus 211 that connects the system controller 205 to the VGA controller 111. The AGP bus 211 employs a data transfer protocol that is a superset of the PCI bus protocol. The AGP bus 211 runs at a clock speed of 66 MHz. The MDM-A 201 is thus able to take advantage of the higher clock rates of 66 MHz VGA controllers and includes the faster and more capable Pentium.RTM. II CPU.
The currently-available Intel MPM 101 shown in FIG. 1 is connected to the system with a 0.8 millimeter pitch connector. The MDM-A 201 will be connected to systems with a 0.5 millimeter pitch connector which increases the number of available connector pins in order to accommodate a second port 215 from the MPM-A 201 to the AGP bus 211.
Personal computer ("PC") manufacturers prefer to develop upgradable PCs that can accommodate new, enhanced components when these components become available. Although the MDM-A device 201 is not currently available, it is desirable for PC manufacturers to produce a PC incorporating the currently-available MPM 101 shown in FIG. 1 that can be, in the future, upgraded by replacing the MPM 101 with an MDM-A 201 shown in FIG. 2. However, because the MDM-A 201 includes additional pins for the second AGP port 215, and because the VGA controller 111 is connected via the AGP bus 211 rather than via the PCI bus 109, the PC system shown in FIG. 1 is not compatible with the MDM-A 201 shown in FIG. 2. A need has therefore been recognized for an upgradable MPM that incorporates the components of the MPM 101 shown in FIG. 1, but is compatible with, and can be replaced by, the MDM-A 201 shown in FIG. 2.